A late 19th century Holbeinesque diamond and enamel bangle

A late 19th century Holbeinesque diamond and enamel bangle
The front of tiered openwork design, set with an old brilliant-cut diamond cluster centre within a polychrome enamel and diamond foliate surround, the shoulders set with old brilliant-cut diamonds to a foliate engraved hinged bangle, circa 1870, inner diameter 5.7 cm, front detachable